Improvement in mariners  logs



G. E. ELLIOTT.

mmmns LOG.

Patented Dec. 7,1875.

N o.170,7Z0.

WITNESSES ATTORNEYS.

N. PETERS. PHDTO-LITHOGRAPHER. WASHINGTON. D. C.

UNITED STAT S,

PA ENT OFFICE.

GEORGE E. ELLIOTT, OE sT. ANDREWS, CANADA.

IMPRCVEMENT IN MARINERS LOGS.

Specification forming part of Letters Patent No. 1 70,720, dated December 7, 1875; application filed November 6, 1875.

To all whom it may concern:

Be it known that I, GEORGE E. ELLIOTT, of St. Andrews, in the Province of New Brunswick and Dominion of Canada, have invented a new and Improved Mariners Log, of which the following is a specification:

In the accompanying drawing, Figure 1 represents a front view of my improved mariners log; and Fig. 2 is a vertical central section of the same on the line a c, Fig. 1.

Similar letters of reference indicate corresponding parts.

My invention relates to an improved mariners log, which registers correctly the speed of a vessel without requiring any particular skill in its use or special calculations. The log may be used without the cumbersome reel and line by being lowered into the water at any suitable part of the vessel by a handle ,or float, being very convenient and reliable in its application.

The invention consists of a concave disk or drag, that acts with greater or lesser force, according to the speed of the vessel, on a rack-bar and spring, which moves, by suitable actuating gearing, the index-hand along a face-dial. The indexhand is retained by a ratchet and pawl, for reading oif the log, and returned to its position by a tension-spring 011 releasing the pawl. I b

In the drawing, A represents a hollow casing, of non-corrosive metal, which is firmly attached at one end to a float or handle, by which it is lowered into the water, and provided at the other end with a strong arm, A, to the outer end of which the bell-crank lever B is fulcrumed at its angle part. The outer end of bell-crank lever B carries a concave disk or drag, O, at slight inclination to the direction of the current, the concavity of which produces a uniform pressure at different angles to the current. The arms of the bell-crank lever B are of equal length to approximate more nearly to the strength of the springs used, and work smoothly and with little friction. The end of bell-crank lever B, near to casing A, enters the recessed outer end of a sliding rack-bar, D, that is guided by its round part in a closely-fitting perforation of the casing, to prevent the entrance of water to the interior of the same. The inner end of rack bar D is attached to a suitable spiral V- shaped or other spring, E, that is fastened with its opposite end to the casin g. The rack E gears with a pinion, a, of a hollow sleeve, b, that passes to the outside of easing A, and carries a dog or carrier, d, with bent-up end, for engaging the indexhand F.

The action of the current on the disk actuates the spring-governed rack, and thereby the carrier d, whose position varies according to the speed of the vessel, the same being in stantly returned as soon as the log leaves the water.

A spindle, 6, passes inside of hollow sleeve b, and is governed at the inside of casing A by a spiral watch spring, f, and provided at the outside with the index-hand F and a ratchet-wheel, g, and spring-pawl g. The carrier 01 forces the index-hand F around the ratchet to the extreme position reached by the pressure of the current on the disk, where the index-hand is retained by the pawl and ratchet mechanism, indicating on a dial of the casing the speed of the vessel, which is read off and registered on the withdrawal of the log.

The resistance of the tension-spring of the spindle gives the hand a steady uniform movement, takes up all slack motion, and prevents it effectually from indicating too much.

The separate action of the carrying-arm and index-hand renders the main spring more durable, without liability to set. and admits the return of the hand to its normal position on the release of the pawl from the ratchet.

The dial and hands may be protected against mechanical injury by floating debris, &c., and against the entrance of water, by a glass front, and the log be used at the bow or other part of a vessel, so as not to be afl'ected by the additional suction or other currents at the stern. It may also be used for determining the velocity of the current of a stream or canal by being introduced from the banks of the same.

The log is simple, durable, and reliable, and allows the direct reading 011' and registering of the speed without requiring special skill or calculation.

Having thus described my inv'enfii0n,I claim as new and desire to secure by Letters Patent- In mariners logs, a sliding spring gdi'rin''d rack, actuated by a concave pressure-disk,

and combined, by transmitting-gear and car- I rier-dog, with a separate] y-turning and springacted index hand, provided with retaining awl and ratchet mechanism, for registering speed of Ve'ssl on dial of easing, substantially in the manner and for the purpose set GEORGE EDMUND ELLIOTT. Witnesses:

T. H. WHITLEGK,

GEO. F. CAMPTON, P. M. 

